272 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



ward being covered with soil. These experiments resulted in no con- 

 trol. The apparent contradiction of these results was due to season- 

 al habits rather than to the ineffectiveness of the poison. In the spring 

 the millipedes were becoming active after hibernation and fed raven- 

 ously on the tender plants at the surface. In the autumn, the pests, 

 going deeper into the soil to pass the winter, were not attracted to the 

 growing plants above the surface. Consequently, when bait was ap- 

 plied in the spring, they were readily attracted, while applications in 

 the fall seeded frames proved inefficient. 



Summary 



Either sodium cyanide, nicotine sulphate solution, or nicotine sul- 

 phate in the form of a dust resulted in comparatively perfect stands of 

 lettuce. 



The plot treated with sodiiun cyanide at the rate of 150 pounds to 

 the acre, when applied in furrows and covered with soil one week be- 

 fore planting, showed an increase of 256 plants over the untreated plot. 



Nicotine sulphate, diluted one part in two hundred parts of water, 

 when sprinkled on a newly seeded bed, resulted in an increase of 224 

 plants as compared with the check. This plot had been previously 

 limed, but as shown in the other tests, lime did not factor as a control 

 measure. 



Two per cent nicotine sulphate as a dust increased the stand 144 

 plants. 



Sweetened poison bait controlled millipedes in the spring but proved 

 inefficient in autumn as a protection in fall seeded frames. 



Mr. E. C. Cotton: Was the same amount of seed used in each case? 

 Mr. J. L. Horsfall: The seed drill was set exactly the same in 

 the treated plots as it was in the checks. 



President Wilmon Newell: The next paper is by F. M. Wadley. 



LIFE HISTORY OF THE VARIEGATED CUTWORM^ 

 By F. M. Wadley, V. S. Bureau of ontomology 



The variegated cutworm- is distributed over most of North Amer- 

 ica and the rest of the world. Its power of sudden increase to de- 



iPublished by permission of the Secretary of Agriculture. 



*Lycophotia margaritosa saucia Hbn.; family Noctuidae; order Lepidoptera. 



